Wireless networks continue to evolve as new communication technologies develop and standardize. Wireless network operators can deploy new communication technologies in parallel with earlier generation communication technologies, and wireless networks can support multiple communication technologies simultaneously to provide smooth transitions through multiple generations of mobile wireless devices. A representative wireless network can include simultaneous support for the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) wireless communication protocol and the Third Generation Partnership Project 2 (3GPP2) CDMA2000 1x (also referred to as 1xRTT or 1x) wireless communication protocol. This representative “simultaneous” wireless network can support circuit switched voice connections through a first wireless network that uses the CDMA2000 1x wireless communication protocol and packet switched connections (voice or data) through a second wireless network that uses the LTE wireless communication protocol. The 3GPP wireless communications standards organization develops mobile communication standards that include releases for Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE) and LTE Advanced standards. The 3GPP2 wireless communications standards organization develops mobile communication standards that include CDMA2000 1xRTT and 1xEV-DO standards. While a dual network mobile wireless device that includes support for both CDMA2000 1x and LTE is described as a representative device herein, the same teachings can be applied to other mobile wireless devices that can operate in dual (or more generally multiple) wireless communication technology networks.
Dual chip mobile wireless devices can include separate signal processing chips that each can support a different wireless communication protocol, such as one signal processing chip for the CDMA2000 1x wireless network and another signal processing chip for the LTE wireless network. In particular, in a dual chip mobile wireless device, each signal processing chip can include its own receive signal processing chain, including in some instances multiple receive antennas and attendant signal processing blocks for each signal processing chip. With separate receive antennas available to each signal processing chip in the dual chip mobile wireless device, pages can be received independently from two different wireless networks, such as from the CDMA2000 1x wireless network and from the LTE wireless network, by the dual chip mobile wireless device. Even when the dual chip mobile wireless device is connected and actively transferring data through one of the signal processing chips to one of the wireless networks, such as the LTE wireless network, the dual chip mobile wireless device can also listen for and receive a paging message through the other parallel signal processing chip from a second wireless network, such as the CDMA2000 1x wireless network. Thus, the dual chip mobile wireless device can establish a device originating or device terminated circuit switched voice connection through the CDMA2000 1x wireless network while also being actively connected to (or simultaneously camped on) the packet switched LTE wireless network. Dual chip mobile wireless devices, however, can consume more power, can require a larger physical form factor and can require additional components (and cost more) than a more integrated “single chip” mobile wireless device.
A single chip mobile wireless device, at least in some configurations, can include a signal processing chip that can support different wireless communications protocols but can be unable to be actively connected to one wireless network and to receive communication from a separate wireless network simultaneously. The single chip mobile wireless device can support multiple wireless communication technologies, such as connections to a CDMA2000 1x wireless network or to an LTE wireless network, but only to one wireless network at any given time. The single chip mobile wireless device can be limited to receiving signals that use one wireless communication technology type at a time, particularly when multiple antennas are used to receive signals for a single communication technology using receive diversity. In a representative embodiment, a single chip mobile wireless device can be able to connect to or camp on an evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (eUTRAN) of the LTE wireless network and also to connect to or camp on a radio access network (RAN) of the CDMA2000 1x wireless network, but not to both wireless networks simultaneously. The single chip mobile wireless device can be registered on both the LTE wireless network and on the CDMA2000 1x wireless network and can therefore form connections with each wireless network singly but not simultaneously. When the LTE wireless network does not support a circuit switched fall back (CSFB) mode or voice over LTE connections, the single chip mobile wireless device can be unable to receive a page from the CDMA2000 1x wireless network when connected to or camped on the eUTRAN of the LTE wireless network. Thus, there exists a need for a method whereby a single chip mobile wireless device can achieve similar functionality to a dual chip mobile wireless device, so that the single chip mobile wireless device can retain the ability to complete a circuit switched voice connection through the CDMA2000 1x wireless network when connected to or camped on the eUTRAN of a parallel LTE wireless network.
This application describes methods by which a single chip mobile wireless device can operate in a multiple network environment supporting connections to both an LTE wireless network and a CDMA2000 1x wireless network while optimizing radio network resources and minimizing radio network signaling requirements.